Having now been in space longer than any other American astronaut, Kelly is currently spending 12 months aboard the space station as part of the One Year Mission, an effort to study the long-term effects of space flight on the human body.

NASA is closely watching Kelly - and his twin brother, Mark Kelly, on Earth - to track his body's reaction to extended weightlessness, isolation, radiation and stress as preparation for the agency's eventual journey to Mars.

"Got to see the #SuperBowl in person after all! But at 17,500MPH, it didn't last long. #YearInSpace" said NASA astronaut Scott Kelly on Sunday after he orbited over California. Levi's Stadium is the oval shape in the center of the photo.

, it turns out that Scott Kelly is a fun astronaut to hang out with. The NASA spaceman is currently spending a year aboard the International Space Station (double the usual stay) and he shared his experiences

. His answers were in part sweet, in part humorous, but all gave a fascinating behind-the-scenes look to the not-so-well known aspects of an astronaut's life in space. Read on to hear about his views on acid pee, Klingon technology and David Bowie.

One of the AMA's youngest interviewers was Simon, who is five years old. He asked: "Could a rogue spaceship sneak up on the space station without being aware, and dock?"
Kelly's answer made us worry about Klingons from Star Trek: "Maybe an alien spaceship with a cloaking device. But not your normal spaceship, no. Unless it had a cloaking device, which doesn't exist, the U.S. Air Force would see it coming."

We think of astronauts as brave people, but perhaps their bravery doesn't come from the derring-do we see in movies such as "The Martian" and "Gravity." Kelly said the creepiest thing he ever does on the job "generally ... has to do with the toilet."
"Recently I had to clean up a gallon-sized ball of urine mixed with acid," he said, adding, "The acid is added to the urine so the urine doesn't damage the machinery that moves it through the system. It keeps it from clogging up the system."

With Kelly having a military background and all, perhaps you'd be forgiven for thinking he crosses his arms so often because he is a stern naval aviator. Turns out, though, that it's a matter of simple physics. And human physiology.
"It feels awkward to have them floating in front of me. It is just more comfortable to have them folded," Kelly wrote.
Another user responded, "Wow, this is something I legitimately never considered. I just thought you were being gangsta."

We think of microgravity as being a very gentle environment for astronauts. They can push off walls with a simple touch, do somersaults effortlessly, and simply float in a sleeping bag to go to sleep. But besides hurting muscles and bones, the environment makes you develop weird calluses, Kelly said.
"The top of my feet develop rough alligator skin because I use the top of my feet to get around here on space station when using foot rails," he wrote.

With the passing of David Bowie earlier this month, space fans have been nostalgic about the many space references in his songs, from "Space Oddity" to "Starman". He even had an album with perhaps the neatest space reference of all time ("The Rise and Fall of Ziggy Stardust and the Spiders from Mars.")
But what was Kelly's favorite song from the Brit's award-winning catalog? Turns out it's "Modern Love". The song appears to be about disillusionment with modern-day life, and especially working for a living. But we still think modern days and working would remain ever more awesome in space.